Studies On Tissue Culture Of Several Chinese Cymbidiums

Chinese Cymbidiums is a part of the terrestrial species of Cymbidium Sw..The orchid culture has a long history of culture in China.Chinese Cymbidium has high ornamental value and economic value,but it is difficult to reproduce naturally,the reproduction cycle is long,the reproduction coefficient is low.A variety of Chinese Cymbidiums were used as plant materials in this study,and the tissue culture technology was further studied to provide a basis for optimizing the tissue culture system of Chinese Cymbidiums.The main results are as follows:1.Non-symbiotic germination of seeds.In this experiment,there were 37 hybrid combinations in total,among which 19 hybrid combinations obtained rhizomes through germination.The Non-symbiotic germination of self-crossing seeds of C.goeringii Guizhou Red',C.sinense 'Si Gangshui'and C.kanran 'Zi Hanlan' were sown between flocculent and powdery seed morphology,The germination rate was significantly increased and the germination time was significantly shortened.10%NaClO solution immersion could accelerate the germination rate and increase the germination amount of the 3 kinds of Cymbidiums,after the seeds were soaked with 10%NaCIO for 10min,the germination time of the 3 kinds of Cymbidiums was 30-50d shorter than that of CK,and the number of seed germination was 4.47-8.35 times of that of CK,the germination rate was significantly higher than that of other treatments.The optimal medium for seed germination of 'Guizhou Red' was:MS+1.0mg/L 6-BA+1.0mg/L NAA+2.0g/L tryptone;the optimal germination medium for 'Si Gangshui' was:modified Hyponex 1+1.0mg/L 6-BA+0.5mg/L NAA;the optimal germination medium for 'Zi Hanlan'was:modified Hyponex 1+1.0mg/L NAA+l00ml/L CM.2.Rhizomes proliferate.The rhizomes of C.goeringii 'Sixi Die'×'Laorui Die',C.tortisepalum'Da Xuesu',C.sinense 'Xiandian Baimo' and C.ensifolium 'Guifei Zuijiu' cultured in light condition proliferated significantly faster than the dark ones.High concentration of 6-BA(1.0mg/L)and NAA(5.0mg/L)were beneficial to the proliferation of rhizomes of C.goeringii 'Sixi Die'x'Laorui Die',low concentration of 6-BA(0.1mg/L)and NAA(1.0mg/L)were beneficial to the proliferation of rhizomes of 'Da Xuesu','Xiandian Baimo' and 'Guifei Zuijiu'.The fresh weight increment coefficients of four species of orchid rhizomes on modified Hyponex 2 medium were 3.67,1.50,1.78 and 1.99 times as much as those on MS medium,which were significantly higher than those on other medias.Add 2 g/L tryptone for 'Sixi Die' × 'Laorui Die' rhizomes proliferation efect best,add 1 g/L yeast extract on the medium had best effect for 'Da Xuesu','Xiandian Baimo','Guifei Zuijiu'rhizomes proliferation.3.Bud differentiation of thizomes.Among the three plant growth regulators,the concentration of 6-BA is the main factor affecting the bud differentiation of the rhizomes of four Chinese orchid species:'Sixi Die'×'Laorui Die' hybrid,`Da Xuesu','Xiandian Baimo' and'Guifei Zuijiu'.The combination of 2.0 mg/L 6-BA+0.5 mg/L Ad+2.0 mg/L NAA was most suitable for bud differentiation of C.goeringii 'Sixi Die'×'Laorui Die' rhizome,the differentiation rate reached to 87.88%.2.0 mg/L 6-BA+1.0 mg/L Ad+0.5 mg/L NAA was most suitable for the differentiation of rhizome buds of C.sinense 'Xiandian Baimo',C.enifolium 'Guifei Zuijiu',the differentiation rates were 100%and 35.71%,respectively.2.0 mg/L 6-BA+2.0 mg/L Ad+1.0 mg/L NAA was most suitable for rhizome bud differentiation of tortisepalum 'Da Xuesu',the differentiation rate reached to 91.58%.The optimum medium components for C.goeringii bud induction were:2g/L Hyponex 2+2g/L tryptone+40g/L saccharose+Og/L AC,the induction rate was 88.89%,and the germination coefficient was 5.00;the optimum medium components for bud induction of C.sinense,C.tortisepalum and C.emifolium were 1 g/L Hyponex 2+20g/L saccharose+ Og/L AC,with bud differentiation rates of 100%,94.44%and 77.78%,respectively.AC concentration was the main factor affecting the differentiation of 4 orchid rhizomes,the germination rate and germination coefficient decreased significantly with the increase of AC concentration.The addition of 2g/L peptone significantly promoted the differentiation of rhizome bud of C.goeringii,but the two organic additives significantly inhibited the differentiation of rhizome bud of 'Da Xuesu','Xiandian Baimo' and 'Guifei Zuijiu'.4.Rooting and transplantin.The rooting effect of IBA was better than NAA.High concentration of auxin(2.0mg/L IBA)was beneficial to the rooting effect of C.goeringii 'Sixi Die'×'Laorui Die',with rooting rate of 86.67%The auxin requirements of C.tortisepalum 'Da Xuesu',C.sinense'Xiandian Baimo',C.enifolium 'Guifei Zuijiu' was lower than that of C.goeringii,and the concentration of 1.0mg/L was more appropriate,,with rooting rates of 80.00%,77.78%and 71.11%,respectively.With pure sphagnum as the transplanting medium,the transplanting survival rate was 100%,fresh weight increased by 1.16g,and new root 2.13,the growth state was significantly better than other transplanting medium.